Wednesday, January 25, 2012

Rainfall on Wednesday morning varied from less than 2, to more than 6 inches in the Onion creek watershed. The heaviest rainfall fell on, and downstream of, the Edwards Recharge Zone in the Barton Springs area. This is reflected in flow of less than 10 cfs at the Onion Creek at Driftwood station on the upstream side of the recharge zone, and the Twin Creeks gage downstream of the recharge zone that reached 700 cfs! In other words, we did get recharge, but it will be temporary and not sustained since the creeks won't continue to flow. However, the ground is saturated enough such that a few inches in the contributing zone could really generate some sustained flow and recharge. Thus, the conditions are primed to get us out of drought--if we get more rain.

*Data from Barton Springs is estimated, but is well above 20 cfs and rising. In a few days there will be some better estimates. Lovelady has leveled off, but these rains will raise the water level in the next few days.

Here is a snapshot of rainfall totals over the past 48 hrs since 1/25/12 4pm (courtesy of the LCRA Hydromet).

There was some significant recharge occurring in the upland (and even in creeks) albeit temporary. Below is a picture of a small tributary of Slaughter Creek with a cave name Brodie Cave, capturing (recharging) all of the streamflow.

Wednesday, January 11, 2012

Despite the above-average rainfall in November and December for central Texas, we remain firmly in Critical Drought conditions. The rains provided some recharge to the aquifer, but the rise and benefit will only be temporary unless substantial rainfall occurs over the next 6 months. Unfortunately La Nina conditions exist, which generally mean drier-than-normal conditions.

Drought Rules

Either Barton Springs OR the Lovelady Well can trigger a drought declaration by the Board. However, BOTH Barton Springs AND the Lovelady Well must be above their respective drought trigger levels to exit a drought declaration.